I know, and yes, forgive me my poor attempt at levity.
Besides, you wouldn’t use water - pure or otherwise - for this.
And of course the fish wouldn’t take to well to oil!
Lets be honest, I just didn’t think this through, did I.
I do recall that back in my playing days, we had some success using transformers submerged in oil to act as power soaks for our valve amplifiers.
Ah, heady days.
Addendum:
It still looks wrong though. Haha.